A sound-absorbing panel comprising a padding layer with heat-bonded synthetic fibers, wherein the padding layer has a first outer surface, a second outer surface and a first thickness, wherein the panel is made of said padding layer with no further layers of a different material between the first outer surface and the second outer surface, wherein the padding layer in at least one portion of panel has a variable density in a direction transverse to the first and second outer surfaces, the density being higher in proximity of the first and second outer layers thereof and being lower in proximity of its inner layer.